Ngc55

[alocky]

Here's a 3.5 hour result on NGC55 from my backyard in Perth. I actually managed to get some good seeing, and it was good to be able to iron a few bugs out of the system. The scope is a 10"f4.5 with a qsi683 camera on a G11, with a 0.953" image scale.
Still some issues with what I think may be stray light causing the ring, but I have an alternative theory that it is fact caused by taking the flats with the focuser in the wrong position.
Full res on astrobin:
http://www.astrobin.com/133436/
cheers,
And thanks for looking!
Andrew.

[RickS]

That turned out pretty well, Andrew.

[atalas]

Nice shot Andrew.

[Rex]

Nice detail Andrew, great shot.

[alocky]

Thanks for the encouragement! I'm slowly getting to the point where I can get the system to deliver its potential, just need to improve the focus stability now.
Cheers,
Andrew.

[Shiraz]

Excellent detail - very nice image. For interest, what CC do you use?

[alocky]

Thanks Ray! I use the Baader Rowe coma corrector, purchased from someone on this site a few years ago now. I set it up as per the specs and have been pleasantly surprised by how well it corrects even a full frame DSLR. The 8083 chip seems tiny in comparison.
Cheers,
Andrew.

[Stevec35]

Nice one Andrew. Good detail and very tastefully processed.

Cheers

Steve

[gvanhau]

Nice shot Andrew.:thumbsup:

By the way, there is discrepancy on exposure time published in astrobin.

Geert

[alpal]

Hi Andrew,
that's looking very nice.
I wouldn't mind having a go at a slight re-process if you wouldn't mind?
A bit less blue & a few other tweaks.
I could post the result here?

cheers
Allan

[alocky]

Of course! Providing you explain what you've done 😄
In fact I really appreciate the effort you and others make here to get discussion going and to challenge us to improve! I thought it was a bit blue too, but decided it gave it a cool feeling.
Cheers,
Andrew

[alocky]

Thanks Geert - 5.3 hrs is correct. 8 ten minute subs for each filter.



Thanks Steve!

[alpal]

Hi Andrew.
OK here is a quick go saved on Astrobin:

http://www.astrobin.com/full/134022/0/

I split the channels & used curves to reduce blue.
I then re-combined.
I then went to LAB mode & adjusted the core of the galaxy
using a feathered mask to increase the yellows & reds.
I also used a mask to sharpen just the bright areas of the galaxy.
I also used Fitswork4 to do a variable flatten on the background.

Is it better?

I could do a lot better with the original 32 bit FITS stacks.

cheers
Allan

[atalas]

A very nice correction on colour Al which allowed the dust lanes to lift better.

[alpal]

Thanks Louie although I feel I could have done a lot more with the original stacks.
I've lost some of the power of the blue when I reduced it
& that was the main colour in the halo.
I think it needed a pseudo luminance layer.

cheers
Allan

[alocky]

I agree, very nice, and the selective masking solves the problem I had with the flat fielding. I might revisit it it as well to see if I can match your result. You are more than welcome to the fits files - I can give you the linear stacks post calibration and registration if you like. I think I can post a link to dropbox if anyone is interested?
Cheers and thanks again for taking the trouble to show what can be done to improve it!
Andrew.

[alpal]

Sure Andrew,
I am doing another processing job right now which will take a long time - from scratch.
I wish more people would give out their stacked 32 bit FITS on this forum.

I've been so busy at work & every time it's Friday or Saturday night it's cloudy.
I can't stay up all night & then go to work in the morning.
Maybe I'll have to wait till I retire before I can put in some proper imaging time?
Living in Melbourne doesn't help either.

cheers
Allan

[Ross G]

Great looking galaxy photo Andrew.

Very nice detail.

Ross.

[alocky]

Thanks Ross!

Here's a link to the integrated fits files L,R G and B
https://www.dropbox.com/sh/zmfi71j2qf0ztre/AACO0OoWX8FgRrIlvXrUzZz7a?dl=0
for anyone wanting to have a play. There's a few interesting challenges in this dataset!
I've also had a go at balancing the channels differently to reduce the blue.
http://www.astrobin.com/133436/B/

[alpal]

Hi Andrew,
thanks for that data.
I processed it & the result is here:
http://www.astrobin.com/full/135002/0/

I have also posted a cropped version attached.
It came out quite different to yours.

cheers
Allan